1. Field of the Invention
This invention relates to apparatus for driving disc memory devices, and, more particularly, to apparatus for driving magnetic cartridges of a particular type for use as peripheral computer data storage.
2. Description of the Prior Art
The particular type of disc cartridge which apparatus embodying the present invention is designed to operate with is the IBM 5440 type. This cartridge is designed for loading into the apparatus from the top. Various vendors other than IBM manufacture and sell disc drive apparatus for use with this type of cartridge. The cartridge is a standard size and shape, and certain of the components within the disc drive apparatus are standard or at least present certain minimum dimensions insofar as their size and spatial relationship to the cartridge inserted in the disc drive apparatus are concerned. Thus, there are certain minimum dimensions for the disc drive apparatus which are more or less standard throughout the industry. However, rack space is at a premium in equipment mounting one or more disc drive units and, where a particular design can be achieved which significantly reduces the rack space required for a disc drive apparatus, an important benefit may be achieved.
The combination of equipment which is required to be mounted in the disc drive apparatus in line with the space reserved to receive the standard disc cartridge requires a front-to-back dimension of 24 inches. The maximum chassis dimension which can be accommodated in a standard 24-inch rack is approximately 22 inches. In those prior art disc drive apparatus of the top loading type which are known, this minimum chassis dimension of 24 inches is accommodated by utilizing a mounting rack of the next larger standard size which is substantially in excess of the minimum front-to-back chassis dimension. This requires mounting racks which are both more expensive in initial cost and wasteful of space, since additional depth is required. This additional depth is needed for the disc drive apparatus, although there may be no other component in the rack that calls for the increased depth, and thus there is actual waste of some space throughout the rack in those portions which mount equipment other than the disc drive apparatus.